It is known that useful information may be obtained using human exhaled breath biomarkers relevant to diseases ranging from cystic fibrosis and asthma to diabetes. Despite considerable efforts to understand the underlying cellular sources and determinants of exhaled compounds, knowledge of the underlying chemical and biochemical processes of exhaled gases remains limited in many cases. For example, cells may be collected and the headspace above the cells may be analyzed for gaseous products. However, the identification of gases in the headspace above cells growing in culture is not a simple task. Most of the gases of interest exist in concentrations so small that their accurate measurement can be a challenge (e.g. pptv to ppqv, 10−12 to 10−15).
The collection and measurement of these trace concentrations requires the fabrication of bioreactors which can accommodate a sufficient number of cells and can allow ready access to the culture medium and headspace for sampling gases with negligible ambient contamination. Prior studies utilized a glass bottle sealed with a septum to culture human lung cancer cells. Headspace gases were sampled by puncturing the septa with a hypodermic needle. A better design to capture and accurately measure headspace gases is needed.